I agree with you but unfortunately these sites almost always have poor usability too.
I'm just joking but then again I'm really not
But as soon as you cut off ways to make the Web more "engaging", it makes it far less interesting for the ads market, so less contents. Even individual content producers (e.g. Youtubers, Twitchers) look for monetization these days.
Something like WebAssembly, then?
In other words, WebAssembly won't cut the Gordian knot, in my opinion.